1. Introducing the Lightmap
2. Special Indoor Lighting Effects
3. Fine-tuning Outdoor Lights

Point_spotlight

Beginners frequently misunderstand the use of point_spotlight. This entity does not emit any light. Instead, it creates a "beam of light" effect in your map. This entity works together with another light entity, most frequently light_spot. So don't ever use this entity by itself.

Turning Off Dynamic Lighting

When using point_spotlight entity, we can usually reduce the resource burden by turning dynamic lighting off. Dynamic lighting allows the light beam to move around in the map. If you have played Half-Life 2, you would remember how each of the scanners has a point_spotlight entity associated to them. So there is a beam of light that shines from each scanner as it flies around the city.

For the most common purposes, we don't need to turn dynamic lighting on. The reduction in resources and framerates is usually dramatic. A handful of point_spotlight entities in your map can easily bring the performance of your map down to its knees.

To turn dynamic lighting off, open the "Object Properties" dialog and bring up the "Flags" tab. Click on "No Dynamic Light".

Volumetric Light